Forced Warm Air H/L

Kevin_52

For the help regarding the fan limit switch. One more Question regarding that topic. You say it is neccessary to have a discharge temp. sensor in the supply duct, but I did not inform you that the system has cooling as well, therefore, would the temp. sensor method still work, or am I forced into adding a dump zone?

Regards,

Kevin

Kevin_52

Is the honeywell fan/limit switch compatable

...with a lennox oil furnace w/3 zones, that has a failed H/L from the factory? it is not currently the conventional Honeywell fan/limit switch

Techman

Fan Limit

Happy Holidays Kevin,For the most part ,a F/L is a F/L.Is the length the same?Does the F/L have a built in heater ? It is under warranty if it is new, as you say.How are the 3 zones set up? With 2 zone's satisfied ,you might be causing the F/L to trip out on the limit ?

Empire_2

I agree w/ Terry.

With 1 zone calling the limit will trip, but there should also be a DAT discharge t-stat that should cycle the unit on and off to prevent the limit from even coming into play. Hey Terry, check out Arzel.com,.....zone system that I think you will really like. Basically uses pneumatics for control....

Mike T.

Techman

Zoned system

Kevin,a simple test would be to read the air temp directly coming out of the A/H and then satisfy two zones and record the temps.If the zones are of different sizes,satisfy the two larger zones to get the worst case senerio.As Mike T suggested a discharge air limit would help also .On the cooling side ,the same applies.Chances are you will probably need an in-warranty compressor before long.That is ,with out a PROPER dump zone!

Empire_2

Kevin

The DAT (discharge Air T-stat) only reports back to a master panel to cycle the system, both heat and cool to optimize the system performance. Now, there are cheap systems that may not have the DAT, but I think you get the picture.

Mike T.